Blast-furnace apparatus



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. J: F. BENNETT.

BLAST FURNACE APPARATUS. N0.- Z97,663. Patented A r. 29, 1884.

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.J.-.F.B.ENNETT. BLAST FURNACE-APPARATUS.

No. 297.663 Patented Apr. 279, 1,884.

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J. F. BENNETT. BLAST FURNACE APPARATUS.

No. 297,663. Pate nt ed Apr. 29, 1884.

NITED' STATES PATENT OFFICE.

JOHN FRANCIS BENNETT, OF PITTSBURG, PENNSYLVANIA.

BLAST-FURNVAC E APPARATUS.

SPECIFICATION forming part of Letters Patent No. 297,663, dated April 29, 1884-.

Application filed January 15, 1883. (No model.) i

To all whom it may concern.-

Be it known that I, JOHN FRANCIS BEN- NETT, residing atPittsburg, in the county of Allegheny and State of Pennsylvania, have invented a new'and useful Improvement in Blast-Furnace Stoves, of which the following is a specification.

My invention relates to improvements in blast-furnace fire-brick stoves in which an atmospheric current forced by a blower to a blast-furnace is raised in temperature by passage through an intermediate stove whose walls and tubes have previously been heated by the passage in an opposite direction of the blast-furnace waste gases; and the objects of my improvements are, first, to decrease frictional resistance of the hot gas or heatedair in passage through the stove; second, to present a large surface for the deposition of the heat and for contact of the cold air; and, third, to secure these ends with simplicity of construction. I attain these objects by the means illustrated in the accompanying drawings, in which- V Figure 1 represents a broken elevation of my improved stove, and Fig. 2 a'vertical section of the same. Fig. 3 is a horizontal section on the line 00 x, and Fig. 4 a similar sec-. tion on the line y y of Fig. 2.

Similar letters refer to corresponding parts in all the views.

A represents either the coldair inlet or th hot-gas outlet, according to the character and direction of the current.

B is either the heated-air outlet or the hotgas inlet, according to the character and direction of the current.

0 represents the outer casing of the stove.

D is an air space or jacket, by which conduction is obviated.

E is the brick wall constituting the stove.

F F F" F are large stones in the top of the stove, whose removal admits of access to the interior for cleaning or inspection purposes. If access below the arches is desired, stones K K K K can be displaced for that purpose.

G G G are vertical abutments for the stones F F! Fl! :EV/II H H H H H are partition-walls form ing chambers I J J J L L-L are the bases, respectively, of the -M is a passage formed by arching the ends O is a cold-air-inlet valve, which admits the atmospheric air, essential to the perfect combustion of the hot gases in their passage through the stove, through small pipes 00 0. into the bottom of the chamber I.

P P PP P P are stones so cut that their outer sides follow the inclination of the walls L L L L, being thus held in place by frictional contact. Their lower inner corners are rounded in quadrant shape, so that when stones are put inposition which are counterparts of each other an arch will be formed, whereby great strength is secured in the structure.

The stones support the fire-brick tubes 1) b b. 7 5

R is a short wall, subserving the double function of dividing the air-blastand of sustai ning the arch. It accomplishes the former end by its peculiar shape, its cross-section formingath'ree sided prism whose pointed end is turned to the inlet A, and the latter purpose by presenting to the point of greatest pressure its thickest portion.' a a a are the fines formed by the partitions H.H H and the tubes I) b b, and by the tubes themselves.

The pipesAand B are constructed in a rounded or bell-mouthed shape, the frustum of cone extending about two diameters of the main body of the pipe and the area at the larger end amounting to about twice that of the main body of the pipe. 'The tubes 1) b b are similarly tapered at their ends, and the upper ends of the partition-walls H H form approximately a semicircle. Bythis construction the velocity of the hot gases or heated air is not materially diminished by passage through the stove, while as large a surface as is requisite for storing sufficient heat to raise the atmospheric air to the desired temperature is presented. Moreover, by-decreasing the obstructions which cause the great frictional resistance incident to blast-furnace stoves as nowconstructed a given engine-power is utilized to a correspondingly-increased extent at the furnace. In other words, a smaller engine-power will suflice to feed air at the same pressure than now required.

Heretofore arched roofs have been employed in furnaces of this character, as also enlarged ends of flues, rounded walls, partitions, and passages, and these I do not broadly claim.

Having thus fully described my invention, what I claim, and desire to secure by Letters Patent of the United States, is

In apparatus for raising the temperature of the air to be fed to a b1ast-furnace, a stove, G, I 5

having cold-air inlet A, sloping wall It, dividing the current, partition-Walls H H H H 11, forming chambers I J J J tubes 1) b b, forming fines a a a, passage M, and heatedair outlet B, substantially as described.

JOHN FRANCIS BENNETT.

Witnesses:

J AMES H. PORTE, F. C. MILLIKEN. 

